Biochar - a natural wonder for land remediation

by The Green ManJuly 13, 2018

Despite its original use some 2,000 years ago deep in the Amazonian rainforest, it is only relatively recently that scientists have begun to realise the potential for biochar, to assist in the remediation of formerly polluted land.

Biochar’s unique properties not only make it highly effective in improving plant growth, it is also proven effective in land remediation efforts as well. For example, in cases such as the Hope Mine reclamation project¹, the first and largest whole-mine reclamation project using biochar undertaken in the U.S. Even though the former silver mine had not been in operation for over 60 years, the refuse and wastage from previous industrial activity had created large piles of toxic rock, preventing the growth of virtually any vegetation. An even greater cause for concern was how the pollution ran directly to the local water supply, with potential impacts lasting many years.

Biochar was introduced into the soil in various test plots and within one year extraordinary results were produced: the test plots containing biochar resulted in a 313% increase in vegetation in comparison to compost-only plots. Biochar plots also held greater soil moisture than plots without, and better slope stability and erosion control were achieved in just one year. Biochar effectively aided in turning a once former barren wasteland into green hillside in a fraction of the time it would have taken using traditional land remediation methods.

Biochar is effective because positively charged chemicals naturally bind themselves to biochar, a process called adsorption. This effect means that heavy metals such as lead and cadmium can bind themselves to biochar, preventing them from contaminating surrounding soil and plant life. Additionally, biochar, being mildly alkaline, stabilises soil pH in acidic soil.

The end result being that biochar has an impressive ability to reclaim formerly unusable land.